3245-62-3Relevant academic research and scientific papers
Polymer-supported oligoethylene glycols as heterogeneous multifunctional catalysts for nucleophilic substitution
Jadhav, Vinod H.,Jeong, Hwan-Jeong,Lim, Seok Tae,Sohn, Myung-Hee,Song, Choong Eui,Kim, Dong Wook
, p. 3577 - 3583 (2013)
We investigated various structurally modified polystyrene-supported oligoethylene glycols (PSoligoEG) in order to find an optimized PSoligoEG by examining the dependence of their catalytic activity on the oligoethylene glycol chain length and the loading level of the oligoethylene glycol portion on the polystyrene support. From this, we found that the PSpentaEG with the highest pentaEG loading had the best catalytic efficacy among the various PSoligoEGs in nucleophilic substitutions. This PSpentaEG absorbed both polar aprotic solvents, such as DMSO, DMF, and acetonitrile, as well as protic media, such as tert-amyl alcohol and aqueous acetone, and swelled considerably. To expand the scope of the PSpentaEG as a heterogeneous catalyst for diverse nucleophilic displacement reactions, we carried out the thioacetoxylation, nitrilation, azidation, iodination, bromination, chlorination, and methoxylation using the corresponding alkali metal salts in the presence of PSpentaEG in various solvents; all the reactions proceeded smoothly, affording the corresponding products in high yields.
Structural modifications in the distal, regulatory region of histamine H3 receptor antagonists leading to the identification of a potent anti-obesity agent
Szczepańska, Katarzyna,Pockes, Steffen,Podlewska, Sabina,H?ring, Carina,Mika, Kamil,Latacz, Gniewomir,Bednarski, Marek,Siwek, Agata,Karcz, Tadeusz,Nagl, Martin,Bresinsky, Merlin,M?nnich, Denise,Seibel, Ulla,Kuder, Kamil J.,Kotańska, Magdalena,Stark, Holger,Elz, Sigurd,Kie?-Kononowicz, Katarzyna
supporting information, (2020/12/07)
A series of 4-pyridylpiperazine derivatives with varying regulatory region substituents proved to be potent histamine H3 receptor (H3R) ligands in the nanomolar concentration range. The most influential modification that affected the affinity toward the H3R appeared by introducing electron-withdrawing moieties into the distal aromatic ring. In order to finally discuss the influence of the characteristic 4-pyridylpiperazine moiety on H3R affinity, two Ciproxifan analogues 2 and 3 with a slight modification in their basic part were obtained. The replacement of piperazine in 3 with piperidine in compound 2, led to slightly reduced affinity towards the H3R (Ki = 3.17 and 7.70 nM, respectively). In fact, 3 showed the highest antagonistic properties among all compounds in this series, hence affirming our previous assumptions, that the 4-pyridylpiperazine moiety is the key element for suitable interaction with the human histamine H3 receptor. While its structural replacement to piperidine is also tolerated for H3R binding, the heteroaromatic 4-pyridyl moiety seems to be essential for proper ligand-receptor interaction. The putative protein-ligand interactions responsible for their high affinity were demonstrated using molecular modeling techniques. Furthermore, selectivity, intrinsic activity at the H3R, as well as drug-like properties of ligands were evaluated using in vitro methods. Moreover, pharmacological in vivo test results of compound 9 (structural analogue of Abbott's A-331440) clearly indicate that it may affect the amount of calories consumed, thus act as an anorectic compound.
Synthesis of Medium-Ring-Sized Benzolactams by Using Strong Electrophiles and Quantitative Evaluation of Ring-Size Dependency of the Cyclization Reaction Rate
Kurouchi, Hiroaki,Ohwada, Tomohiko
, p. 876 - 901 (2019/12/30)
Benzolactams with medium-sized rings were synthesized via the electrophilic aromatic substitution reaction of carbamoyl cations (R1R2N+═C═O) in good to high yields without dilution. These reactions were utilized to quantitatively examine the extent of retardation of medium-sized ring formation, compared to five- or six-membered ring formation. The order of reaction rates of formation of cyclic benzolactams is six- > five- > seven- > eight- > nine-membered ring at 25 °C. The present reaction provides a route to eight- A nd nine-membered benzolactams.
Discovery of benzotriazole-azo-phenol/aniline derivatives as antifungal agents
Lv, Min,Ma, Jingchun,Li, Qin,Xu, Hui
supporting information, p. 181 - 187 (2017/12/04)
A series of benzotriazole-azo-phenol/aniline derivatives were prepared and evaluated for their antifungal activities against six phytopathogenic fungi such as Fusarium graminearum, Fusarium solani, Alternaria alternate, Valsa mali, Botrytis cinerea, and Curvularia lunata. Among them, compounds IIf, IIn, and IIr showed a broad-spectrum of potent antifungal activities. Especially some compounds displayed 3.5–10.8 folds more potent activities than carbendazim against A. alternata and C. lunata. Notably, compounds IIc, IIm, and IIr exhibited good protective and therapeutic effects against B. cinerea at 200 μg/mL. Their structure-activity relationships were also discussed.
Synthesis and antibacterial activity of 3-benzylamide derivatives as FtsZ inhibitors
Hu, Zhongping,Zhang, Shasha,Zhou, Weicheng,Ma, Xiang,Xiang, Guangya
supporting information, p. 1854 - 1858 (2017/04/04)
The emergence and spread of multidrug-resistant strains of the human pathological bacteria are generating a threat to public health worldwide. In the current study, a series of PC190723 derivatives was synthesized and investigated for their antimicrobial activity. The compounds exhibited good activity against several Gram-positive bacteria as determined by comparison of diameters of the zone of inhibition of test compounds and standard antibiotics. Compound 9 with a fluorine substitution on the phenyl ring showed the best antibacterial activity in the series against M. smegmatis with the zone ratio of 0.62, and against S. aureus with the zone ratio of 0.44. The results from this study indicate that based on the unique 3-methoxybenzamide pharmacophore, compound 9 may represent a promising lead candidate against Gram-positive bacteria that are worthy of further investigation
Hydrogen-Bonded Homoleptic Fluoride-Diarylurea Complexes: Structure, Reactivity, and Coordinating Power
Pfeifer, Lukas,Engle, Keary M.,Pidgeon, George W.,Sparkes, Hazel A.,Thompson, Amber L.,Brown, John M.,Gouverneur, Véronique
supporting information, p. 13314 - 13325 (2016/10/22)
Hydrogen bonding with fluoride is a key interaction encountered when analyzing the mode of action of 5′-fluoro-5′-deoxyadenosine synthase, the only known enzyme capable of catalyzing the formation of a C-F bond from F-. Further understanding of the effect of hydrogen bonding on the structure and reactivity of complexed fluoride is therefore important for catalysis and numerous other applications, such as anion supramolecular chemistry. Herein we disclose a detailed study examining the structure of 18 novel urea-fluoride complexes in the solid state, by X-ray and neutron diffraction, and in solution phase and explore the reactivity of these complexes as a fluoride source in SN2 chemistry. Experimental data show that the structure, coordination strength, and reactivity of the urea-fluoride complexes are tunable by modifying substituents on the urea receptor. Hammett analysis of aryl groups on the urea indicates that fluoride binding is dependent on σp and σm parameters with stronger binding being observed for electron-deficient urea ligands. For the first time, defined urea-fluoride complexes are used as fluoride-binding reagents for the nucleophilic substitution of a model alkyl bromide. The reaction is slower in comparison with known alcohol-fluoride complexes, but SN2 is largely favored over E2, at a ratio surpassing all hydrogen-bonded complexes documented in the literature for the model alkyl bromide employed. Increased second-order rate constants at higher dilution support the hypothesis that the reactive species is a 1:1 urea-fluoride complex of type [UF]- (U = urea) resulting from partial dissociation of the parent compound [U2F]-. The dissociation processes can be quantified through a combination of UV and NMR assays, including DOSY and HOESY analyses that illuminate the complexation state and H-bonding in solution.
Efficacy of novel phenoxyalkyl pyridinium oximes as brain-penetrating reactivators of cholinesterase inhibited by surrogates of sarin and VX
Chambers, Janice E.,Chambers, Howard W.,Funck, Kristen E.,Meek, Edward C.,Pringle, Ronald B.,Ross, Matthew K.
, p. 154 - 159 (2016/12/06)
Pyridinium oximes are strong nucleophiles and many are effective reactivators of organophosphate-inhibited cholinesterase (ChE). However, the current oxime reactivators are ineffective at crossing the blood-brain barrier and reactivating brain ChE in the intact organism. Our laboratories have developed a series of substituted phenoxyalkyl pyridinium oximes (US patent 9,227,937 B2) with the goal of identifying reactivators effective in crossing the blood-brain barrier. The first 35 of the series were found to have similar in?vitro efficacy as reactivators of ChE inhibited by a sarin surrogate (phthalimidyl isopropyl methylphosphonate, PIMP) or a VX surrogate (nitrophenyl ethyl methylphosphonate, NEMP) in bovine brain preparations as previously observed in rat brain preparations. A number of these novel oximes have shown the ability to decrease the level of ChE inhibition in the brains of rats treated with a high sublethal dosage of either a sarin surrogate (nitrophenyl isopropyl methylphosphonate, NIMP) or the VX surrogate NEMP. Levels of reactivation at 2?h after oxime administration were up to 35% while the currently approved therapeutic, 2-PAM, yielded no reduction in brain ChE inhibition. In addition, there was evidence of attenuation of seizure-like behavior with several of the more effective novel oximes, but not 2-PAM. Therefore these novel oximes have demonstrated an ability to reactivate inhibited ChE in brain preparations from two species and in?vivo data support their ability to enter the brain and provide a therapeutic action. These novel oximes have the potential to be developed into improved antidotes for nerve agent therapy.
Organocatalysis of nucleophilic substitution reactions by the combined effects of two promoters fused in a molecule: Oligoethylene glycol substituted imidazolium salts
Jadhav, Vinod H.,Kim, Ju-Young,Chi, Dae Yoon,Lee, Sungyul,Kim, Dong Wook
, p. 533 - 542 (2014/01/06)
Oligoethylene glycol substituted imidazolium salts were synthesized as promoters for a range of SN2 reactions, and their efficiency was examined. These tailor-made organic promoters enhanced the nucleophilicity of alkali metal salts significantly through the combined effects of two promoters (oligoethylene glycols and imidazolium salts) in a single molecule. The effects of the oligoethylene glycol side chain length, ionic liquid anions, nucleophiles, and substrates were investigated systematically. [hexaEGmim][OMs] and [dihexaEGim][OMs] showed the highest efficiency for SN2 reactions using alkali metal salts. The role of the terminal hydroxyl groups of the oligoethylene glycol moiety was assessed by examining the relative S N2 yields of chlorination and bromination. The results showed that the hydrogen bonding strength of the hydroxyl groups with the nucleophile is very important. The mechanism for the excellent promotion of SN2 reactions by oligoEGILs was examined by quantum chemical calculations. The results showed that the oxygen atoms in the oligoethylene glycol portion and the ionic liquid anion act on the counter cation K+ or Na+ as a Lewis base, to enhance the reactivity of the metal salts significantly.
NOVEL ANTIMICROBIAL COMPOUNDS
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Page/Page column 17, (2013/04/10)
A new class of biotin protein ligase (BPL) inhibitors that have antibacterial activity against multiple Staphylococcus aureus isolates, including clinically important methicillin-resistant S. aureus (MRSA) are disclosed that are non-toxic.
